1. Field of the Invention
This invention, in the preferred embodiment, relates to battery powered hand held lamps, commonly known as flashlights, or when in compact form as pen or pocket lights. More specifically, the invention relates to quasi-blackout applications and uses that require fast visual recovery in darkness and minimum personal exposure of the operator of the device.
For example, the use of high intensity white light reflected from white papers, such as maps or writing pads, adversely affects the eyes and could influence vehicular or other accidents, if the viewer was subsequently required to make a fast judgment in another field of view where the illumination levels were then low. This invention assists in avoidance of such hazards by confining the light beam and by making it convenient to quickly select a white light or a colored light, such as red, from the hand held lamp.
As illustrated and described herein, the invention is applied to a cylindrical flashlight of the penlight type. Broader applications of the principles and features disclosed include uses in varied lighting apparatus where a convenient and rapid change in color of the illumination is required. Features and techniques disclosed reduce the costs of manufacture and assembly and improve operating reliability.
2. Related Prior Art
Portable lighting devices such as flashlights and compact hand lamps of the cylindrical penlight variety are well known in the art. Typical of the art for such devices is a U.S. Pat. No. 2,818,499 (Moore) that discloses a penlight having a tubular casing with a bulb holder, assembled in one end of the tube, a switching mechanism in the opposite end of the tube, and means for holding the dry cell batteries in fixed positions. U.S. Pat. No. 4,516,628 (McDermott) discloses a dual color penlight which has its color changed by rotating a component along the axis of the flashlight.